package com.heima.kafka.testDemo;

import org.apache.kafka.clients.consumer.ConsumerConfig;
import org.apache.kafka.clients.consumer.ConsumerRecord;
import org.apache.kafka.clients.consumer.ConsumerRecords;
import org.apache.kafka.clients.consumer.KafkaConsumer;

import java.time.Duration;
import java.util.Collections;
import java.util.Properties;

public class ConsumerQuickStart {
    public static void main(String[] args) {
        //2.配置消费者的连接信息
        Properties properties =new Properties();
        //2.1配置消费者的连接地址
        properties.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG,"192.168.244.100:9092");
        //2.3配置消费者组
        properties.put(ConsumerConfig.GROUP_ID_CONFIG,"group1");
        //2.3配置消息的key和value的序列化器
        properties.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG,"org.apache.kafka.common.serialization.StringDeserializer");
        properties.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG,"org.apache.kafka.common.serialization.StringDeserializer");
        //1.创建消费者对象
        KafkaConsumer<String,String> consumer = new KafkaConsumer<String, String>(properties);
        //3.订阅主题
        consumer.subscribe(Collections.singletonList("kafka-first"));
        //4.获取消息,保证消费者线程一直存活
        while (true) {
            ConsumerRecords<String, String> consumerRecords = consumer.poll(Duration.ofMillis(1000));
            //遍历获取的消息集合
            for (ConsumerRecord<String, String> consumerRecord : consumerRecords) {
                System.out.println(consumerRecord.key());
                System.out.println(consumerRecord.value());
            }
        }
    }
}
